Processing of elastic polychloroprene



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United Stated mm" commune;

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, (cusp-u I Dt fllt invention'relnteitoprocessin'g of I rubber-like masses of polychloroprenes known to the trade as neoprene, andmorepartieulsrlylto 9 M1 rubber and neoprene have,

The preierable amounts of the use in the neoprene during the-mastication or millin aretrom03-peruntto2peroenta1- desired. The

m m or hi l i alth'attororqinarymillingoineopreneqfl compounds, for; 7045,07 r.. althoushor thattype o1 neopreneknownas'neoprene GK i invention the sulttnl compoeltionn; The following are given in illustraotthe' nvention.-

new by wei fiht':

pisp rt'ios in common, it 18 known that my mom 1 51, mmfioumot 32%; H P ooa vulcanization accelerator for mo in mum m 7 w rubber compounds, whereas it i; sold as are- A tarderoivulconization'ioruseinneoprene ooni- 1' 1- B pounds.Also,whereasheattendstosdtenrub-" o i F n: e m fiwfloi'ia'itimit:i::::::::::::::i:::::::: .39.. lo

ablydue to. continued Hence, v 3 1 WW t empmp motto moon hero mo has moro iowin'; cii otine, 3 cal-to neoprene. f mimian nitm analysis, bswelttz 01 35.80%;

"l'hqhew pluticiuers tor the elastic polyohloro f i 'fi u :'flfl: 7 oted neoprene; whereb'ytoprovide new 2:. llia ationa, a guru lulmfe o'oci to tetrainethyl I PM? "film P o them! "PM'f' v 'oreased-visoositmha've theiormula MMAQS t e 'g prenewasworkinrwellon'themill. Themillinsc -1! SI wasoonduoted for 11% minutes at about 194 1''. "\L Total milllnl'thne-mthe o bothA and e 3;"Plast'1cities were thenruno'n saniples ottheae "f'? H Y m xes in the scott plastonietefr after z ou o st'a'ndinz' The plas'wmeter temperature'wais 21 .wm fsf fggg w f so 1''. and theplastomete'r reedinfi woo taken on the aryl hetioci'clic :r uns' ur s lene xdlo fi the test was oo'lninon" to the same cyclo-alk ylene zroup I 3 by a procedure w l u??? a a n and m are seperate radical; they'may I u 1 or'unlike. The invention also extends to .tn'e, ldcrivot c -ortnciroc thlazoles (in which A B I themercapto-hm en is substituted or added u-v'mmmdm 135 v I to) which are capable of liberating the treethio- "v? "f I01 und th'presen 1 I .thQ meta'fam monium? fi fi'iitltitufi'iamfis or m w w m the remaining h i in Ilium "salts'as won Isthe esters, e. I. the zine "Imam m inch in thickness of 81x- -n pgperldyl, hen methylene 'umne db tenths inch thick sample of the respective mix. 1 m mnidme n, dmmophenyl, ben'zoyl F'he results plainly show that under the above esters; also the dlsulphides or the irc tmoz'oiet. condition! of the mix B, containing The milling of the neopren with the plasticizer 5 tmmlei has F f should preferably be carried out in th gi e riled oonslderably more than the mix A containr other oompounding ingredients that would ini no added che i terfere with the plosticizing action of the chemi- Immpte 2 m2"; m": rtmrnzmrts; i To other we wt an hm. since they do not neopren GR and mixes were made as i'ollows: terfere with the ooid-pio ticizing action. A B O D The chemicals are round to bench powerful plastioisers i'or neoprene that the neoprene can N to ON be mlrkedly softened by mastication in air at ;5'mm ordinary temperatures. i-mcroopto-u-dilmtn i-tmuo Dlllticlzer. tor

Mixing and testim was conducted as under E:-

A'divided mill was used for the milling and A and B were milled at the same time. Likewise C and D were milled at the same time. The results on B and D as compared to the blanks A and C definitely show a powerful plasticizlng action for these two l-mercapto thiazoles.

When the softened neoprene is compounded in the usual fashion, the resulting compounds vulcanize excellently and give vulcanizates that resist various types of heat aging better than vulcanizates that do not contain these chemicals.

' Examples of other chemicals included in the scope of this invention are, 1-mercapto thiazole, 4-methyl-l-mercapto thiazole, S-ethyl-l-mercapto thiazoie, l-mercapto-3,4-tetramethylene thiazole, 1-mercapto-3,4-dimethyl thiazole, 1-

mercapto-S-butyl thiazole, zinc salt of 3-methyll-mercapto thiazole, zinc salt of l-mercapto thiazole, zinc salt of 4-methyl-1-mercapto 'thiazole, zinc salt of S-ethyl-l-mercapto thiazole, zinc salt of l-mercapto -3,-tetramethylene thiazole, zinc salt of l-mercapto-IlA-dimethyl thiazole, zinc salt of l-mercapto-S-butyl thiazole, hexamethylene imine salt of B-methyl-l-mercapto thiazole, piperidine salt of 3-methyl-l-mercapto thiazole, pi-

peridine salt of l-mercapto thiazole, piperidine salt of 4-methyl-1-mercapto thiazole, piperidine salt of '3-ethy1-1-mercapto thiazole, piperidine salt of l-mercapto-3,4-tetramethylene thiazole,

piperidine salt of l-mercapto-3A-dimethyl thi-. azole, piperidine salt of 1-mercapto-3-butyl thi I 'azole, diphenyl" guanidine salt of 3'-methyl-1- mercapto thiazole, diphenyl guanidine salt of l-mercapto thiazole, diphenyl guanidine salt of 4- methyl-1-mercapto thiazole, diphenyl guanidine salt of 3- ethyl-l-mercapto thiazole, diphenyl guanidine salt of l-mercapto-3,4-tetramethylene thiazole, diphenyl guanidine salt of l-mercapto- 3,4-dimethyl thiazole, diphenyl guanidine salt of l-mercapto-Ii-pbutyl thiazole, ammonium salt of l-mercapto-ES-methylthiazole, ammonium salt of -mercapto thiazole, ammonium salt of 4methyl l l-mercapto thiazole, ammonium salt of 3-ethyll-mercapto thiazole, ammonium salt of l-merazole, dinitrophenyl ester of S-ethyl-l-mercaptd thiazole, dinitrophenyh ester of 1-mercapto-3,4- tetramethylene thiazole. dinitrophenyl ester of I-mercapto-SA-dimethyI thiazole. dinitrophenyl ester of 1-mercapto-3-butyl thiazole, benzoyl ester of 3-methyl-1-mercapto thiazole, benzoyl ester of l-mercapto thiazole, benzoyl ester of 4- methyl-l-mercapto thlazole, benzoyl ester or 3- ethyl-l-mercapto thlazole, benzoyl ester of 1- mercapto-3,4-tetramethylene thiazole, benzoyl ester of 1-mercapto-3,4-dimethyl thiazole, benzoyl ester of lemercapto-3-butyl thiazole, piperidyl methyl-3-methyl thiazole sulfide, piperidyl methyl ester of 3-methyl-1-mercapto thiazole, piperidyl methyl ester 01. l-mercapto thiazole, piperidyl methyl ester of 4-methyl-l-mercapto thiazole, piperidyl methyl ester of 3-ethyl-1-mercapto thiazole, piperidyl methyl ester of l mercapto-3,4-tetramethylene thiazole. piperidyl methyl ester of 1-mercapto-3,4-dimethyl thiazole, piperldyl methyl ester of l-mercapto-3- butyl thiazole, the 'disulflcle o! 3-methyl-1-mercapto thiazole, disulphide o1 l-mercapto thiazole, disulphide of 4-methyl-1-mercapto thiazole, disulphide of B-ethyI-I-mercapto thiazole, disulphide of 1-mercapto-3,4-tetramethylene thiazole, disulphide of 1-mercapto-3,4-dimethyl thiazole. and disulphide oi l-mercapto-Zi-butyl thiazole, etc.

The invention may be applied to the conversion of all forms of neoprene including solid unvulcanized neoprene, reclaims, neoprene cements, neoprene dispersions. etc.

The present invention allows of converting elastic polychloroprene and particularly neoprene GN to a material which can more easily be processed in the factory.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1 A process of preparing a plastic conversion product of an elastic polychloroprene which comprises milling a mixture containing the same and 1-mercapto-3,4-dimethyl thiazole, for a time and at a temperature sufiicient to markedly reduce the viscosity of the polychloroprene.

2. A plastic conversion product of polychloroprene and 1-mercapto-3,4-dimethyl thiazole.

3. A plastic conversion product of polychloroprene and 1-mercapto-3,4-diall yl thiazole.

4. A process of preparing a plastic conversion product of an elastic polychloroprene which comprises milling a mixture containing the same and l-mercapto-3,4-dialkyl thiazole', for a time and at a temperature sufllcient to markedly reduce the viscosity of the polychloroprene.

' LOUIS H. HOWLAND. 

